Editorial & Source Standards

Sourcing hierarchy

Facts on this site are sourced in this order: (1) statutes and administrative code, (2) federal and state agencies, including EPA and Iowa HHS, (3) county and city government, and (4) recognized technical standards incorporated or referenced by law. Commercial websites, news articles, and other contractors' marketing pages are not acceptable sources for consequential claims here.

Verification dates

Consequential claims carry a visible CHECKED date recording when the claim was last checked against its official source. When a source changes, the claim and its stamp are updated together; a stale stamp is treated as a defect.

Claims this site refuses to publish

• Specific prices or price ranges for radon work — pricing belongs to the provider.
• Response-time, availability, or outcome commitments on a provider's behalf.
• Invented local statistics, testimonials, reviews, staff bios, or years-in-business claims.
• Health claims beyond what EPA, Iowa HHS, or county public health publish.
• Per-city radon severity comparisons that official data does not support.

AI assistance disclosure

Drafting and maintenance of this site use AI assistance. Every consequential fact is still human-checked against the official sources listed below before publication, and the correction process applies regardless of how a sentence was drafted.

Corrections

Report an error via the contact page with the page and the claim. Verified corrections update the page and its verification date.

Official sources used across this site

• EPA — Radon — U.S. Environmental Protection Agency
• EPA Consumer's Guide to Radon Reduction (PDF) — U.S. Environmental Protection Agency
• EPA A Citizen's Guide to Radon (PDF) — U.S. Environmental Protection Agency
• EPA — How Much Can a Radon Mitigation System Cost? — U.S. Environmental Protection Agency
• EPA Map of Radon Zones — U.S. Environmental Protection Agency
• Iowa HHS — Radon — Iowa Department of Health and Human Services
• Iowa HHS — Radon Resources — Iowa Department of Health and Human Services
• Iowa HHS — Radon in K–12 Schools — Iowa Department of Health and Human Services
• Iowa HHS — Radon Resources, Radon-Resistant New Construction section — Iowa Department of Health and Human Services
• Iowa HHS — Radon Testing & Lab Certification and Mitigation Credentialing — Iowa Department of Health and Human Services
• Iowa Administrative Code 641—Chapter 44 — Iowa Legislature
• Iowa Legislature — Iowa Code chapter 136B — Iowa Legislature
• Linn County Public Health — Radon — Linn County, Iowa
• Linn County — About Linn County — Linn County, Iowa
• City of Cedar Rapids Building Services FAQs — City of Cedar Rapids

All links retrieved and verified July 24, 2026.